1. Field of the Invention
The present invention relates to carpentry tools and, more specifically, to a tool for marking angled lines on a board.
2. Summary of the Invention
The disadvantages of the prior art are overcome by the present invention which, in one aspect, is an angle marking saw guide for marking a plank having a front side that includes a planar marking member including a protractor portion extending upwardly from a flat ruled straight edge portion having a straight edge. The protractor portion ends in an arcuate edge having a constant radius from a pivot point disposed at a central location of the straight edge portion. A plurality of graduated angle markings is disposed adjacent to the arcuate edge. The protractor portion defines an arcuate slot that is concentric with the arcuate edge passing through the protractor portion. A first detent is defined at a first end of the arcuate edge and a second detent is defined at second end of the arcuate edge. The second end is angularly opposite from the first end. A planar reference member includes a substantially rectangular portion having a front edge and an opposite back edge and a substantially triangular portion extending laterally from the rectangular portion. The triangular portion includes a first angled edge and a transverse second angled edge that meets the first angled edge at a vertex. The marking member is pivotally affixed to the reference member with a fastener disposed adjacent to the vertex. The first angled edge has an angle relative to the front edge so that the triangular portion extends no further than the straight edge when the marking member is rotated fully in a first angular direction and the second angled edge having an angle relative to the back edge so that the triangular portion extends no further than the straight edge when the marking member is rotated fully in a second angular direction opposite from the first angular direction. A vertical wall portion depends downwardly from the front edge and is configured to engage the front side of the plank so as to maintain the reference member in a fixed angular relationship with the front side. A lip surface extends upwardly at an angle between 5° and 85° from the back edge of the reference member and is configured to facilitate lifting of the reference member from the plank. A setting bolt extends upwardly from the reference member through the arcuate slot defined by the protractor portion. A setting nut is engaged with the setting bolt and is configured to apply force to the protractor portion so as to hold the marking member in a fixed angular relationship with the reference member when the setting nut is secured tightly against the protractor portion and configured to allow free angular movement of the protractor portion with respect to the reference member when the setting nut is not secured tightly against the protractor portion. A stopping structure extends upwardly from the reference member so as to limit rotational motion of the marking member in the first angular direction by engaging the first detent and in the second angular direction by engaging the second detent. The stopping structure ends in a pointing member that is configured to point at the graduated angle markings so that when the pointing member points at a selected one of the graduated angle markings, the straight edge has an angle relative to the vertical wall portion that corresponds to the selected one of the graduated angle markings.
These and other aspects of the invention will become apparent from the following description of the preferred embodiments taken in conjunction with the following drawings. As would be obvious to one skilled in the art, many variations and modifications of the invention may be effected without departing from the spirit and scope of the novel concepts of the disclosure.